Recording device for telephone sets



Sept. 20, 1938. BONN 2,130,336

RECORDING DEVICE FOR TELEPHONE SETS Filed D80. 5, 1936 2 Sheets-Sheet l Sept. 20, 1938. F.-BONN 2,130,336

RECORDING DEVICE FOR TELEPHONE SETS Filed Dec. 5, 1936 2 Sheets-Sheet 2 Patented Sept. 20, 1938 UNITED STATES PATENT OFFICE 2,130,336 RECORDING DEVICE FOR TELEPHONE SETS Friedrich Bonn, Surth, near Cologne, Germany Application December 5, 1936, Serial No. 114,299 In Germany August 2, 1935 2 Claim.

of a mechanism which is mounted on the base of the telephone set on top of the rotary finger dial and coupled with the dial.

The devices hitherto suggested for this purpose, and having a recording device mounted beside or beneath the set are not sufiiciently reliable in commercial use and, so far as I have observed, partly require constructional changes in the telephone sets and therefore do not meet the practical requirements.

According to one known construction, the mechanism for recording the numbers which have been dialed is accommodated in a casing which is arranged co-axially to the dial of the telephone set.

However, this device is also unsatisfactory inasmuch as the whole casing has to be turned when operating the dial plate and very complicated constructional means are required for supporting the type printing device within the rotary casing in a stationary position, covering the rotatable dial of the telephone set. Moreover, the printing of the numbers which have been set has to be effected while the dial returns to its normal position. Hence the driving power of the spring mechanism which has to accelerate the whole rotating unit and at the same time has to actuate the printing device, must be rather considerable.

Consequently the operating force which in the setting operation serves for accelerating the movable masses which are rather considerable and furthermore for winding up the spring mechanism has to be relatively great. of course, this is a disadvantage of the known apparatus.

It is the object of the invention to obviate these drawbacks of the known recording devices. To this end, a numeral type wheel is connected to the shaft on which the additional dial is mounted, in such manner that it participates in the rotation of the shaft as the additional dial is wound up, while the numeral type wheel is locked by a mechanism when the dial starts turning back and is released by the mechanism for returning into its normal position ,shortly before the dial has reached normal position and after the dialednumber or digit has been printed on the recording strip.

Hence, my new device has a stationary rather than a rotating casing and moreover it 'efiects the printing at a later instant, namely shortly before the dial has returned to normal and independent of the power which returns the dial to normal.

It will be understood that in this case it is not necessaryto derive the power required for the printing from the return-spring but the momentum ofreturning masses in which previously energy had been stored may be utilized for the printing.

Theduration oi the individual telephone calls may be recorded on the recording paper strip in a simple manner by causing the paper strip with the aid of a clock-work to move at a constant;

speed independently from the printing action past a recording stylus or pencil as long as the set is in use.

For a complete understanding of my invention the following detailed description should be read in connection with the acco panying drawings inwhich Fig. 1 is a front elevation of a telephone set, having mounted on it a recording device according to the invention;

Fig. 2 is a side elevation of the set shown in Fig. 1;

Fig. 3 is a longitudinal section of the recording device on line 3-3 in Fig. 1;

Fig. 4 shows, in larger scaleand in front elevation, the printing device in its normal position;

Fig. 5 shows the same front elevation,shortly prior to the releasing of the printing device;

Fig. 6 shows diagrammatically the arrangement of the paper strip in the printing device, and the device for marking the duration of the calls; and

Fig. 7 shows the ribbon guides and the device for moving the ribbon.

The recording device is enclosed in a casing 76 which may be fastened to the supporting plate 2 by any suitable means not shown in detail, since such attaching means are immaterial so far as the present invention is concerned.- The plate 2 is attached to the telephone set by means of a clamping frame I which corresponds in its form to the shape of the base of the telephone set.

By means of a wall or partition 3 the casing 76 is divided into two superposed compartments A and B. Rotatably mounted in the partition 3 -is the center or main shaft l0 carrying at its inward end a lever 9 ofi'set away from wall 3 so that by means of its projecting finger or stud H it engages the O-hole of the dial 8 of the telephone set. The outwardly projecting end of the shaft l0 has fixed to it the dial l2. Hence the two dials l2 and 8 are mechanically coupled with one another. This dial I2 is under the influence of a torsion spring l2 housed in the protruding central portion l2 of casing 18 and connected between a fixed point 16' of casing .18 and shaft N. This spring, while not absolutely necessary for the operation of the device (which could be operated alone by the telephone dial spring, not shown here), is advisable to use as an auxiliary, so as not to overload the telephone dial spring.

Mounted on the shaft Hi, within the compartment B, is the control disc I! having a partially curved recess l4 and a release pin l5 (Fig. 4). The control disc i3 is shown in its normal position and the straight edge of its recess l4 engages the projecting portion ll of the bell crank it which is pivotally mounted at Ma and acted upon by the spring I817. The free end I! of bell crank l8 swings in the path of movement of the arm 2| of a release lever 20 pivotally mounted at 20' and under the influence of a spring 20'. Another branch '22 of the lever 20 lies in the path of movement of the pin l5. Secured to bell crank ii at 23 is the printing member or type lever 24 having-a little hammer 25 of rubber placed oppositely to a number type wheel 26 presenting the numerals l, 2, 3, etc. In one rotational direction the number type roller 26 is positively coupled with the dial-carrying shaft l and thus with the dial H, by means of the gears 28, 29 and 30 while in the opposite rotational direction. a resilient coupling such as torsion spring 25" is interposed between the toothed wheel 20 and the numeral type wheel 25 thus permitting the dial i2 to return to normal although the numeral type wheel 26 is prevented from rotating. To this end a locking mechanism is provided consisting of a ratchet wheel 3| having ratchet teeth 32 and being rigidly connected to the number type wheel 26. and a pawl 33 which is pivotally mounted on the lever 25. Under the action of the tension spring 35, one end of which is fast to the arm 2! of the lever 20 and the other end of which is fast to the pawl 38, the pawl 33 having at its free end a tooth 31 adapted for engagement with the ratchet wheel 3| is held against a stop 38 of lever 25.

Rotatably mounted on the stud 4? is the paper drum 46. Under the action of the driving roller 54 having a roughened or toothed surface frictionally engaging the paper strip, the strip 58 is unwound from the roller it), thence it runs over the guiding members 49, 50, 52, 53 and is wound up on the winding drum 55. The winding drum 55 is mounted on the plate 55 which is slidable in the direction indicated by the arrow and acted upon by a spring 56 in such manner that drum 55 is resiliently held against the driven roller 54 and paper strip 48 lying on it, thus the paper strip 48 is prevented from slipping on the roller 54 and at the same time the roller 55 is driven in the winding direction. It will be understood that the roller 55 including its slidable mounting plate 55 is gradually displaced in the direction of the arrow, for accommodating the distance between the centers of the rollers 54 and 55 to the amount of paper wound up on the roller 55. Furthermore, by means of the upwardly bent free end 51 of the plate 55 it is possible to move the roller 55 back from the driving roller 54 as indicated by the arrow in order to render it possible to take the roller 55 with the paper reel off from the plate 55 (Fig. 6).

In order that the printed numerals of thecall number or digit may be typed with the proper spacing on the paper strip in the dialing opera- \tion, a shifting mechanism is provided for the driving roller 54. To this end bell crank it has I pivotally mounted at the end of its arm a pawl 58, which coacts with the ratchet teeth 6.0 provided on the rim of the driving roller 54 and moves these teeth 80 in a clockwise direction a step suflicient so that the numerals of the dialed call number are typed with the proper spacing in a successive order on the paper strip so as to be easily readable (Figs. 4 and 5). p The paper strip 48 is besides continuously moved for the duration of a call, in order to record the duration of the call by means of a clock-work of any suitable conventional construction (not shown) which is accommodated in the compartment A. This clockwork may be of any well known type and therefore is not specifically illustrated in the drawings. The clock-work drives the driving roller 54 so as to wind up the paper strip on the winding roller 55. The paper feed or drive by means of this clock-work is automatically started when the subscriber lifts the receiver-from its forked cradle 'Il through the medium of the arm 18 fastened to the cradle and engaging, with its forked end 19 the pivoted lever 42 which in turn, with its pin 6i may engage any suitable element of the clock-work by which it is arrested when the receiver is hung up while it is released when lifting the receiver. These auxiliary features are not shown in the drawings since they are immaterial for the present invention and its understanding.

The mechanism for recording on the paper strip the start and end of a call consists of a lever 38 (Fig. 6) pivoted at 39 and held against the pin H of the lever 42, under the action of the spring All. The lever 42 is connected with the cradle 11, in the manner described above. When the receiver is hung up, the lever 42 is so positioned that the pin ii is in a position above the nose 43 of the lever 38. When the receiver is lifted, the lever 32 moves intothe position indicated in dotted lines in Fig. 6, i. e., beneath the nose 43. By this movement the pin tl presses against the nose 53 and causes the lever 38 to swing in counter-ciockwise direction and to engage the angle piece (it which is disposed underneath the type roller 25 the free end of the angle piece extending underneath and parallel to paper strip 48. The corresponding portion of the type roller 26 has been out off in the drawings to show the angle piece M. In the free portion of the angle piece M is a small hole or recess (not shown) engaged by the pin 55 when it is actuated. The paper strip GE! passes between the angle piece 44 and the pin 35, and each time the receiver is lifted and hung up and the lever 62 swings in counterclockwise direction, the pin 45 makes a small hole or depression in the paper strip. It will be understood that a writing pen orpencil may also be used instead of the pin 45. a

The endless typewriter ribbon 52 (Fig. 7) runs over the ribbon roller 63. the guides 54, 65, 56 and 51 and round the type wheel 26. By the resilient member 68 connected with the guide 61 the ribbon 52 is held under slight tension. It will be understood that any other suitable means may be used for feeding the printing-ink to the type wheel such as an ink roller.

The ribbon 62 is moved by means of the pawl 59 pivoted under spring action on the lever 10. The lever with its free end ll engages the recess or notch of the disc 12 fixed on the dialcarrying shaft l0. Now, when the disc 12 is turned in the direction of the arrow in the setting operation, the free end Ii of the lever it which is pivoted at 12 is lifted. the pawl 89 engages the teeth M oi the ribbon. roller 68 and moves the roller 63 including the ribbon 62.

In order to render it possible to make any ad= ditional notes by hand on the portion of the paper strip carrying the respective recorded call number, an aperture I5 is provided in the top wall portion of the casing, above the paper guide ii.

The operation of the device is as follows:

In the normal position the parts of the mechanism are in the position shown in Fig. 4. Now, when lifting the receiver, the lever 42- moves from the position shown in full lines in Fig. 4 into the position shown in dotted lines, whereby the clockwork for the paper feeding mechanism is released by means of the pin 8! and permitted to operate.v

Simultaneously the lever 38 is swung and produces a perforation on the paper strip 48.

The setting of the numbers is now effected by means of the supplemental finger hold dial i2 operated in the conventional manner to operate the conventional dial 8. The rotary movement of the dial i2 is transferred to the dial 8 of the telephone set by the dial-carrying shaft l6 and the lever 9. By the train of gears 28, 29, 30 the type wheel 25 is rotated accordingly in the direction indicated by the arrow in Fig. 4 so that the number or digit of the type wheel 26 corresponding with the dialed character stands opposite to the hammer 25 when each single dialing operation is finished.

In the dialing operation the disc I3 is turned in the direction indicated by the arrow in Fig. 4. The projection ll of the lever l6 thereby slides along on the incline of the recess N and the lever I6 is lifted on its fulcrum l6a into the position Fig. 5, thus tensioning the helical spring No. The pawl 59 thereby rotates the paper driving roller 54 through a predetermined angle. Due to the rotary'movement of the disc IS the pin i5 disengages the lever 20 so that the latter is swlmg round its fulcrum 20a under the in- 'fluence of spring 20b in a clockwise direction and thereby its free end 2! is moved into the return path of hell crank arm l9 as shown in Fig. 5. Simultaneously the pawl 33 is also swung clockwise and its locking tooth 31 engages the ratchet teeth 32 of. the wheel 3| and thereby prevents this wheel from rotating clockwise.

Now, whenthe finger of the operator disengages the dial l2, it returns to normal in the usual manner under the action of spring l2. The parts It, 20, 33 andthe type wheel 26 on the other hand are kept in their displaced position shown in Fig. 5, up to a predetermined instant shortly before the dial l2 has reached normal and when disc i3 is about to arrive, clockwise turning, in the position shown in Fig. 4. At this instant, which is shown in Fig. 5, the pin l5 contacts the lever arm 22 and lifts it into the position Fig. 4, thus releasing arm IQ of bell crank l6 and allowing its detent II to snap into cam recess ll under the action of the spring liib. The hammer 25 is thereby impelled against the type lying in front of it and the respective type is printed on the paper strip 48 by the medium of the ribbon 62. When this operation is finished, lever 22 rises slightly higher so that, as shown in Fig. 4, pawl 31 becomes disengaged from ratchet wheel 3| and the latter together with type wheel 26 return to normal under the action of the coupling or torsion spring 26. I

The same cycle or sequence of operations will be repeated with every single dialing operation so that the numbers or digits are successively typed or printed on the paper strip. When the receiver is hung up, the lever 42 is moved back into its normal position and acts again upon the lever 38 which in consequence thereof again presses or prints a mark into or onto the paper strip. Simultaneously the spring-actuated member 6i locks the clock-work so that the movement of the paper strip 48 is stopped. From the two marks made on the paper strip 48 by the lever 38 the duration of the call may be computed corresponding to the speed of the paper strip, while the printed number indicates the subscriber with whom the call was made. The incoming calls are also recorded, at least as to their duration, as the lever 88 is operated each time the receiver is lifted or hung up. False recording or falsifications are prevented because the real printing is efi'ected only shortly before the dial returns to normal. For the same reason, the power required for the printing action is materially reduced.

It will be understood that various modifications in the constructional form of my device can be made in accordance with the diiferent shapes of telephone sets, without departing from the scope of my invention.

Having now described my invention, what I claim is:-

I. In a call recording device directly attachable to automatic telephone sets, a stationary casing containing the recording device and,attachable to the selector base of the telephone to cover its conventional selector disc, said recording device having an operating shaft and a visible recorder selector disc mounted thereon and having call characters similar to those arranged on the conventional disc, means for coupling said recorder selector disc with the telephone selector disc, a type wheel carrying call numeral units corresponding to those on said selector discs, gearing between said type wheel and said shaft to positively rotate said type wheel into dialing position the same relative extent as the selector discs when the latter are moved into a dialing position, means for arresting said type wheel in dialed position to permit the latter to return alone to normal position and means .tending to return the type wheel to normal position, a cam ,element on said shaft for controlling said arresting means to arrest the type wheel'and hold it in arrested position while the selector discs return to normal position and to release the type wheel shortly before the discs have arrived in normal position, a printing hammer cooperating with said type wheel to print the dialed character, and means, controlled by said arresting means, for releasing said printing hammer shortly before said type wheel is released to return to normal position.

- 2. In a call recording device directly attachable to automatic telephone sets, a stationary casing containing the recording device and attachable to the selector base of the telephone to cover its conventional selector disc, said recording device having an operating shaft and a visible recorder selector disc mounted thereon and having call characters similar to those arranged on the conventional disc, means for coupling said recorder selector disc with the telephone selector disc, a. type wheel carrying call numeral units corresponding to those on said selector discs, gearing between said type wheel and said shaft to posithe same relative extent as the selector discs when the latter are moved into a dialing position, means for arresting said type wheel in dialed position to permit the latterto return alone to normal position but tending to return the type wheel to normal position, a cam element on said shaft for controlling said arresting means to arrest the type wheel and hold it in arrested position while the selector discs return to normal position and to release the type wheel shortly before the discs have arrived in normal position, a spring operated printing hammer arranged in cooperative relation with said type wheel, a second cam des,1so,sse

mal position.

FRIEDRICH BONN. 

